The present invention is directed, in general, to video processing systems and, more specifically, to an apparatus and method for correcting color degradation and other signal degradation in a video image.
The colors in a video image displayed on a television screen or the monitor display of a personal computer (PC) frequently exhibit differences from scene shot to scene shot due to a variety of reasons. In order to maintain constant color appearance from scene shot to scene shot, all cameras and even the television receivers must be set to the same colorimetry standards. Often, this is not done with sufficient care and there are noticeable variations in color appearance. The result is that the color appearance of programs, as viewed on a television receiver, varies significantly from receiver to receiver and from time to time even on the same receiver.
There is therefore a need in the art for improved systems and methods for maintaining constant color from scene shot to scene shot in a video image. In particular, there is a need for color correction apparatuses for use in television receivers, personal computers, video cassette recorders, and the like that correct color differences from scene to scene in a video image. More particularly, there is a need for color correction apparatuses that correct the colors of objects in a video image to match the true colors of those objects.
To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide an apparatus for correcting the color of objects appearing in a video image. In an advantageous embodiment of the present invention, the apparatus comprises: 1) a frame buffer capable of receiving and storing a first video frame from an incoming baseband video signal; 2) a memory capable of storing known pixel data corresponding to a plurality of known icons, the known pixel data comprising true color data values associated with the plurality of known icons; and 3) a color correction controller capable of comparing captured pixel data from the stored first video frame with the known pixel data stored in the memory and detecting a first actual image of a first known icon appearing in the stored first video frame, wherein the color correction controller is further capable of comparing a first true color data value associated with the first known icon and a first actual color data value associated with a first actual color in the first actual image of the first known icon and, in response to the comparison, determining a first color correction factor associated with the first actual color data value.
According to one embodiment of the present invention, the color correction controller uses the first color correction factor to correct the first actual color data value in the first actual image in the stored first video frame.
According to another embodiment of the present invention, the color correction controller identifies in the stored first video frame a first unknown object having associated therewith a second actual color data value substantially equal to the first actual color data value and wherein the color correction controller uses the first color correction factor to correct the second actual color data value of the first unknown object in the stored first video frame.
According to still another embodiment of the present invention, the color correction controller is capable of determining from the first color correction factor a second color correction factor associated with a third actual color data value.
According to yet another embodiment of the present invention, the color correction controller identifies in the stored first video frame a second unknown object having associated therewith a fourth actual color data value substantially equal to the third actual color data value and wherein the color correction controller uses the second color correction factor to correct the fourth actual color data value of the second unknown object in the stored first video frame.
The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.
Before undertaking the DETAILED DESCRIPTION, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms xe2x80x9cincludexe2x80x9d and xe2x80x9ccomprisexe2x80x9d and derivatives thereof mean inclusion without limitation; the term xe2x80x9corxe2x80x9d is inclusive, meaning and/or; the phrases xe2x80x9cassociated withxe2x80x9d and xe2x80x9cassociated therewithxe2x80x9d and derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term xe2x80x9ccontrollerxe2x80x9d means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.